Benzene is a cyclic aromatic hydrocarbon used as a solvent and reactant in a variety of laboratory, commercial, and industrial applications. Large quantities of benzene are also emitted into the environment in motor vehicle emissions, crude oil spills, and emissions from the production of coke from coal. Although the toxicological effects of benzene have been studied in adult animals, the effects on the developing organism have not been extensively determined. The purpose of the following experiment is to: (1) identify methods sensitive to the neurobehavioral effects of developmental exposure to benzene and (2) attempt to characterize any long-term neurobehavioral deficits following exposure of rats to benzene during the postnatal period of development.